Compressor-unloading mechanism



Patented Sept. 2o, l1927.

' UNITED STATE s PATENT oFFicE.

WADE H. WINEMAN,'OF CHICAGO, ILLINOISHAJSSIGNOR T0 SULLIVAN MACHINBY COMPANY, A. CORPORATION 0F MASSACHUSETTS. I

COMPRESSOR-UNLOADING MECHANISM.

Application led January 14, 1921. Serial No. 437,235.

ing Without t-lie expenditure of the comthe necessary pressed medium for effecting Other objects movements of the unloadcr.

of m invention will appear iii the course of.

the ollowing specilication and the appended claims.

In the accompanying drawings I have shown forppurposes. of illustration one embodiment which my invention may Aassume in ractice.

n these drawings,

Fig. 1 is a side elevation, partially broken away, of a compressor plant provided with my improved unloading mechanism.

F ig, 2 is a vertical section taken on line 2--2 of Fig. 1 through the illustrative form of my unloading mechanism showing details of construction, certain parts being shown in elevation to facilitate illustration.

For purposes of illustration, I have shown my improved compressor unloading mechanism employedin combination witha compressor 1, having a cylinder 2 in which is 3,'said piston serving to cause entrance of air to the com ressor cylinder through an intake 4 contro led by an intake control valve 5 of the balanced type and discharging compressed air througha discharge chest 6 andpipe line' 7 to a receiver 8. For the purpose of controlling thefoperation of the intake controlling valve 5, I` have provided an improved means, as herein illustrated, comprising a valvestem 9 4operative to raise vand vlower the valve', thereby openin f and closing the latter, said valve stem 9 eing controlled by a' pistonflO movable in a cylinder .11 which communicates at its upp`e`r end with an enlarged clearance `chamberI 12.v yThe clearance chamber communicates by way l'of apipe 13 with the line 14 which-connects the compressor intake pro er with the intake controlling valve 5. y reason of this connection, variations in pre'ssureoccasone reciprocable a piston der 11 that one arm of the bell cran throug by the open and closed positions of the halve 5 may be transmitted to the chamber 12. y/The piston l() is provided about its periphery with an annular groove 15 having a shoulder 15 arranged at a slight-'angle to `the horizontal,

For the purpose of controlling the move- E' ments ofthe piston 10, I provide controlling means herein illustrated as comprising a diaphragm 16 mounted in a casing 17 and subjected to receiver pressure through a line l 18 leading to the receiver. A heavy spring 19 is arranged between any adjustable abutment block 20 and a head '21 which presses. /upon the lower side of the diaphragm and tends to resist downward movement of the diaphragm under rec iver pressure. Mov- `able with the head 21 is a stem 22, to which are adjustably secured spacially separated nuts .23 and 24, these nuts being adapted to cooperate respectively with bell cranks 25 and 26 so located with respect to the c lin- 25 may engage theshoulder 15 when the iston is in the position which it occupies W en the valve 5 is closed and so that an arm ol the bell-crank 26' may engage the lower end of the piston 10 when the piston is raised to a position corresponding to fullopen of the valve 5. It will be noted that a spring 27 extends between the bell cranks 25 and 26 and this spring is designed'to maintain them with the piston engaging arms always in position to enga in the piston or the lower end o the piston, when ossible. An o ening 28 is provided Ih the wall of t e cylindenll to per-` mit the bell cranks 25 and 26 to engage the piston 10.

From the oregoi'n description, taken in connection vwith the rawings, the mode 4of voperation of my improved unloadingl mechanism will be readily apparent. W en the compressor is operating to compress fluid, the intake valve 5, will 'be openand accordingly pressure substantially equal to atmospheric pressure will prevail in the clearance chamber 12. Durin thisl time, the spring 19 will hold the diap ragm in raised posi- 'crank i-n engagement with the piston 10 and d so `hold the latter in elevated position..

e the notch The nut 23 having been moved downward will release the bell crank 25 which, under the action of the spring 27,l will move so that its arm projecting into the cylinder 11 will engage in the groove 'l5 and cooperat- 4ing with the shoulder 15 prevent upward movement of the piston 10. In view. of the yfact that the valve 5 isclosed, a vacuum will be produced in the clearance chamber 12 so .that upon fall in receiver pressure 4and the raising of the stem 22 as a result thereof, whereby release of the engagement of the bell crank 25 with the shoulder l5 is effec'ted, the piston 10 will be forced upward by atmospheric pressure acting upon its lower end through the open end of the cylinder 11. It will be understood that the pipe line 13 is of a relatively small diameter so that pressure changes occurring in the intake of the compressor may not be absolutely instantaneously transmitted with full eli'ect to the clearance chamber 12, i. e. so that the vacuum in chamber 12 may en dure long enough to raise the piston l0.

' From the foregoing description, it will be'4 noted that I have provided an limproved unloading mechanism in which no compressed `fluid is requisite to eii'ect operation of thev actuating mechanism and in which the coni trol by receiver pressure is -effected by the 'l dersto condition in the intake of the compressor.

-While I'have in this application specifidally described one form which my inven-l tion ma assume in practice, it will be unfor purposes of illustration and that the inl vention 4may be modified and embodied in 'other forms without departing from its spirit or the scope ofthe ap ended claims.

What I claim as new and esire to secureby Letters'Patent iszv 1. compressor unloading mechanism comprising in combination, a valve controlling the in ake of a compressor, and means operated by'iiuid pressure to move said valve to open position, including a member having changes in v2. A compressor .unloading mechanism comprising, in combination', a valve controlling the intake of a compressor, yand means controlled by the pressure conditions in the vcompressor intake resulting from movement of said valve for valve- 3. In a compressor controlling me'clianism a valve. operative when held -in .one position ling the position of sai that this form of the same is vshown valve position va response of the latter to said fluid pressure causing movement of saidv to unload a compressor, and actuating means for saidI 'valve including an element constantly subject,.on.its opposite sides, to atmospheric pressure and pressure in the compressor-at a point beyond said valve.

4. Ina compressor controlling mechanism,

to unload a compressor, and actuating means for said valve" including an element con-- stantly subject, on its opposite sides, to pressure vin the compressor at a point beyondsaid valve and 'to a pressure which exceeds the` minimum value of said first mentioned pressure.A

5. In a compressor controlling mechanism, an intake closure valve, and operating means therefor including compressor discharge pressure controlled means and means governed thereby responsive to vacuum conditions resulting from closure of said valve.

6. In a compressor controlling mechanism,

a valve whose actuationi7 controls the loading of a compressor, (pressure responsive means for actuating sai valve, and fluid pressure controlled means for mechanically controlling the movement of said first mentioned means.

7. In a compressor controlling mechanism,

a valve whose actuation controls the loading of a compressor, pressure responsive. means for actuating said valve, and a '.(iuidv pressure controlled locking mechanism governing the-instant of movement of said actuat- 8. A" compressor controlling mechanism comprising, in combination, a valve controlling a ycompressor intake a iston controlva ve, means for transmitting to said piston the pressure variations in the intake of the compressor at a point beyondsaid valve, and meansfor controlling the response of said piston to said (pressure variations, said last mentione pressure.

means being responsive to receiver a vvalve operative when heldin one position compressor controlling' mechanism comprising, in combination, a valve-operative when in one position to effect unloading ofja compressor, means responsive to lui pressure for varying the position o f saidf valve', .means'for transmitting luid pressure variations resulting form unloading said -compressor to said valve l}"*'i' o sition varying' means, and means. cooperating with sai rying means to control the ling unloadervalve, fluid pressure .means forl operating saidvalve, means for transmitting iis iiuidl pressure variations resulting from the cl ure of said valve to said last mentioned means, and means responsive to receiver .having a single surface exposed to variable pressure, said surface being exposed constantly to pressure variations arising solely from closure and opening of said valve.

l2. In a compressor controlling mechanism, an element movable to effect unloading and loading of a compressor, means for mdving said element exerting a force thereon tending to move the same, and compressor discharge pressure controlled means for preventing actuation of said element by said means except at a predetermined maximum desired compressor discharge pressure.

13. In a compressor controlling mechanism, an element movable to effect' unloadling and loading of a compressor, means for moving said element adapted alternately to exert forces to move the same in opposite directions, and com ressor discharge pressure controlled means or mechanically preventing actuation of said element by said forces in .either direction except at a predetermined compressor discharge pressure.

14. In a compressor controlling mechanism, an element movable to cause loadingl and unloading of the compressor, means operative to cause opposite movements of said element, and compressor discharge' pressure Acontrolled means including a member movable in opposite directions as compressor dis- 15. A compressor controlling mechanism,

including a valve operative when open to load a compressor and when closed to. unload the same, a member operatively connected with said valve and movable to different positions to open and closesaid valve, and multi-latch means cooperating with said member to lock it in said different positions and movable to release -said member, said means being governed by compressor discharge pressure.

16. A compressor controlling mechanism including a vvalve operative when open to load a compressor and when closed to unload the same, a member operatively connected with said valve and movable to different positions to open andclose said valve, said member being acted on by an unbalanced force tending to move it to its opposite position substantially as soon as it reaches either position, and multi-latch means cooperating with said member tolock it in saiddiferent positions and movable to release said member, said means being governed b compressor discharge pressure.

' 17. he method of loading a motor comressor unit, which comprises controlli the oading pneumaticall as a function o the suction caused b a inlet passages o the compressor. In testimony whereof I afiix` my signature. WADE H. WINEMAN.-

rop of pressure in the 

